I don't think a concept of a fractional ownership exists because, well, it's not yours.
If you really want some guarantee that your immediate radius will meet some sort of standards, it sounds like you'd want to be part of an HOA. I personally would never want to be part of one (who likes being told what to do?) but they could help protect property values from that one neighbor who could be a problem.
"Everyone should maximize the income from their property up to the limit of law" is a recipe for for having no neighborhoods or communities. It's the usual fallacy of treating people as fungible commodities.
HOAs are terrible, they are inevitably staffed with busybodies. We can agree on that!
It certainly is in San Francisco at least. Well, probably not literally zoning, but regulations around it make the home owners in an area de facto owners of it in many ways.
I see the current housing crisis as a direct result of this.
You’re asking rational actors to make irrational decisions. The results are what you’d expect.
That would be unthinkable today though.
As I mention in a sibling comment, you might see changes in a decade or two, but no sooner.
I am not opposed to efforts related to increasing the housing supply (although I do think it’s a fool’s errand in the Bay Area as demand is insatiable due to the tech industry and foreign money seeking a safe asset store), I’m just describing the uphill climb these endeavors face. It’s hard to fiddle with a core component of the economy (property law).